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Who first explained Brownian motion and made a convincing case for the existence of atoms?
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The explanation for Brownian Motion was first presented by Albert Einstein.
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How does the approximate number of atoms in the air in your lungs compare with the number of breaths of air in the atmosphere of the Earth?
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They are the same.
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Why can atoms not be seen with a powerful optical microscope?
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Atoms are smaller than the wavelength of visible light.
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What is the purpose of a model in science?
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Models help visualize what we cannot see, and make predictions about what we can.
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What is a nucleon?
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Protons or neutrons
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Since atoms are mostly empty space, why don't we fall through a floor we stand on?
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Electrical repulsion
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What is the most abundant element in the known universe?
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Hydrogen
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Where did the heaviest elements originate?
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Fusion of light elements in stars
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What does the atomic number of an element tell you about the element?
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The number of protons
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What are isotopes?
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Atoms of the same element that contain different numbers of neutrons.
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What is a compound? Give three examples.
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Pure chemical materials that consists of more than one molecule. Water, ammonia, and methane.
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How does a molecule differ from an atom?
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Molecules are composed of one or more atoms.
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How do matter and antimatter differ?
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Antimatter has negative nuclei and positive electrons.
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What is the evidence that dark matter exists?
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Gravitation pulls on the stars in the galaxies.
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How does the arrangement of atoms in a crystaline substance differ from that in a noncrystalline substance?
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Crystals have regularly repeating internal structures of atoms.
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